Electrochemical Preparation of Silicon and Its Alloys from Solid Oxides in Molten Calcium Chloride

Abstract

Electroreduction, or electrodeoxidation, of pelleted SiO2 powder (left image) or its mixture with other metal oxide powders in molten CaCl2 produces pure Si powder (right image), or the respective silicon alloy powder. Being advantageous by simplicity and resulting in less CO2 emission, the electrochemical approach has an energy consumption that is below 13 kWh (kg of Si)−1.